matchms.filtering.metadata_processing.add_parent_mass module

matchms.filtering.metadata_processing.add_parent_mass.add_parent_mass(spectrum_in: Spectrum, estimate_from_adduct: bool = True, overwrite_existing_entry: bool = False, estimate_from_charge: bool = True, clone: bool | None = True) → Spectrum | None[source]

Add estimated parent mass to metadata (if not present yet).

Method to calculate the parent mass from given precursor m/z together with charge and/or adduct. Will take precursor m/z from “precursor_mz” as provided by running add_precursor_mz. For estimate_from_adduct=True this function will estimate the parent mass based on the mass and charge of known adducts. The table of known adduct properties can be found under matchms/data/known_adducts_table.csv.

Parameters:

  • spectrum_in – Input spectrum.

  • estimate_from_adduct – When set to True, use adduct to estimate actual molecular mass (“parent mass”). Default is True. Switches back to charge-based estimate if adduct does not match a known adduct.

  • overwrite_existing_entry – Default is False. If set to True, a newly computed value will replace existing ones.

  • estimate_from_charge – Default is True. If set to True, the charge will be used to estimate the parent mass. Adduct of the form [M+H]+, [M+H]2+, [M-H]- etc are assumed.

  • clone – Optionally clone the Spectrum.

Returns:

Spectrum with added parent mass, or None if not present.

Return type:

Spectrum or None